Why don't you create a "change language" button in the game settings that would open a screen with language options?
Viewing post in Warrior of the North Wood comments
Because to have that button, I would then need to implement that feature. Localization is a very big task. There's a ton of text to translate, and many things don't translate well from one language to another so having a local speaker to proof read and adjust the text is a huge undertaking. Then there's that I'd need to modify the text engines, every prompt, every UI element with text on it, to reflect the text from that region. As a one-person developer, that's just too much work and would delay the game for months, if not years, and cost me way more money than I'm getting back in support and donations. At this time, it's just not feasible.
I wish I could help you out translating it at least in Russian, but I'm highly hesitant about my overall ability to make it high quality. Granted while I can translate most of the text from English to Russian, it's grammar and punctuation (I think is the word?) is what concerning me. And I'm a native speaker mind you! So yeah, better off hiring a specialist who'll do a good job so you wont have to blush from emberrasment due to a poor translation xd. By the way, can't wait for you to finish up your rework! Hopefully it wont take ages, yeah?